I was at Southwest BMW today trying to see how much each of the maintenance items cost if I were to get them done, I know, I know, they will charge you an arm an a leg. Hehe. They said that fluids such as coolant, brakes, and oil is $159.99 while the spark plugs are approx. $440. Fine. Then I had asked about the transmission fluid and differential fluid, the response I had received was that the transmission fluid and differential fluid does not need to be changed and it is a "lifetime interval." He said I won't have to worry about it until at least 100k miles. Is that true. He also said that if I change the transmission fluid, that my fluid can free up the shavings inside the transmission and ruin it. If that's the case, I don't want my car's transmission to die at 100k. Should I go get it done elsewhere since they will not do it for me or should I not worry and not change or look at it until 100k miles? They said it goes the same for the differential fluid.

Also, is there a way to reset the vehicle's computer for maintenance myself? Some things, I cannot set like the spark plugs or the brakes fluid. I can only set the oil change interval in my iDrive.